I found my ktec system to be loud at the wrong times i.e. on the motorway then too quiet when giving it stick. It was the centre box'd version mind.
Each to their own really, best advice to the OP would be to go to a meet and ask somebody for a demonstration of their ktec system. There's loads of 172's around with them on.
My final word on Ktec's exhausts would be if their own were any good would they "acquire" Fred's Yozzasport exhausts and sell them if they could design them better themselves. I understand them selling Milltek etc because they're big names by specialist exhaust companies, but them selling yozza's is like BTB selling ktec systems.